Limit Test for Chloride | Principle, Procedure and Experiment

Limits test for chloride is a semi-quantitative analytical test. It is performed to identify the traces of chloride impurities which are likely to be present in a substance.

The quantity of chloride impurity in an official substance is often small. So, the visible reaction response of any test for that substance is very small.

The test is done by production of color and compared with that of the standard solution.

Principle of limit test for chlorides

The chloride impurities in the substance are allowed to interact with silver nitrate solution in presence of nitric acid. This leads to the formation of silver chloride which is white in color. Since the quantity of chloride impurity is low, it forms an opalescence instead of a precipitate.

The formed opalescence is compared with that of standard solution against a uniform illumination.